This proposal outlines a research and career development plan that builds on Dr. Gray's existing training and allows her to: 1) gain expertise with in vitro and in vivo methods to study the neurobiology of cognitive impairment; 2) acquire detailed knowledge of techniques and advances in mitochondrial research; 3) solidify skills to characterize botanical products and perform rigorous complementary and alternative medicine research; and 4) build and strengthen the skills needed for success as an independent investigator. Dr. Gray's superb mentorship and collaborative training team are all located at Oregon Health and Science University (OHSU) making it an ideal setting for the K99 phase of this award. In addition to providing world-class training in basic and translational research techniques, numerous courses and seminars are available at OHSU to strengthen the communication, leadership and grant writing capabilities essential for achieving her long-term career goal of conducting independent research on neurologically active botanical and dietary interventions. The goal of the proposed research is to determine how the medicinal plant Centella asiatica (L.) Urban (CA) modulates mitochondrial function and antioxidant response to elicit its neuroprotective and cognitive- enhancing effects. CA is an Ayurvedic herb used to improve cognitive function, an effect supported by studies in humans and numerous rodent models. Our lab has shown that CA water extract (CAW) can improve learning and memory in aged wild-type as well as Tg2576 mice, an Alzheimer's Disease (AD) model of beta- amyloid (A) accumulation, and protect neuroblastoma cells against A-induced cell death. Our preliminary in vitro and in vivo data show that CAW activates the endogenous antioxidant response pathway and induces mitochondrial biogenesis. This proposal will determine how each of those pathways contributes to the neuroprotective and cognitive-enhancing effects of CAW. In Aim 1 Dr. Gray will be trained in and apply the more physiologically relevant in vitro model system of primary neuronal cell culture to determine the molecular mechanism by which CAW protects against A toxicity. In Aim 2, a battery of behavioral assessments will be learned and used to determine which aspects of cognition are altered by CAW, and how its antioxidant and mitochondrial effects contribute to these cognitive-enhancing effects. Aim 2 will also explore the preventative potential of CAW by assessing the cognitive effects and underlying mechanisms of long-term CAW treatment. This work will address critical gaps in our understanding of the mechanism of CAW and how mitochondrial and antioxidant pathways interact and participate in modulating neuronal health and cognition using powerful in vitro and in vivo models of AD. The results and techniques established here will help identify specific targets for future therapeutic intervention with botanical or dietary agents in the context of AD a well as other conditions with cognitive impairment and will lead to better-informed clinical trials of such treatments. The skills and training provided by the K99 award will launch Dr. Gray's active, independent research career.